* [PATCH v1] kbuild: Add KBUILD_VMLINUX_LIBS_PRELINK @ 2025-11-19 4:27 Tiezhu Yang 2025-11-21 7:01 ` Nathan Chancellor 2025-11-22 1:35 ` Nathan Chancellor 0 siblings, 2 replies; 7+ messages in thread From: Tiezhu Yang @ 2025-11-19 4:27 UTC (permalink / raw) To: Nathan Chancellor, Josh Poimboeuf, Ard Biesheuvel, Huacai Chen Cc: linux-kbuild, linux-efi, loongarch, linux-arm-kernel, linux-riscv, linux-kernel In order to only link libstub to the final vmlinux, it can not use the current KBUILD_VMLINUX_LIBS, just add KBUILD_VMLINUX_LIBS_PRELINK. This is preparation for later patch, no functionality change. Link: https://lore.kernel.org/lkml/pq4h7jgndnt6p45lj4kgubxjd5gidfetugcuf5rcxzxxanzetd@6rrlpjnjsmuy/ Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> --- There is a long discussion in the previous patch: https://lore.kernel.org/lkml/20250928085506.4471-1-yangtiezhu@loongson.cn/ This version is based on 6.18-rc6, split the generic parts out into a separate patch to avoid merge conflicts, the other parts will send out after the merge window. Makefile | 1 + scripts/link-vmlinux.sh | 5 ++--- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/Makefile b/Makefile index d763c2c75cdb..69485f47b794 100644 --- a/Makefile +++ b/Makefile @@ -1199,6 +1199,7 @@ KBUILD_VMLINUX_OBJS := built-in.a $(patsubst %/, %/lib.a, $(filter %/, $(libs-y) KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y)) export KBUILD_VMLINUX_LIBS +export KBUILD_VMLINUX_LIBS_PRELINK export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds ifdef CONFIG_TRIM_UNUSED_KSYMS diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index 433849ff7529..e72d3254b93f 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -61,12 +61,11 @@ vmlinux_link() shift if is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT; then - # Use vmlinux.o instead of performing the slow LTO link again. objs=vmlinux.o - libs= + libs="${KBUILD_VMLINUX_LIBS_PRELINK}" else objs=vmlinux.a - libs="${KBUILD_VMLINUX_LIBS}" + libs="${KBUILD_VMLINUX_LIBS} ${KBUILD_VMLINUX_LIBS_PRELINK}" fi if is_enabled CONFIG_GENERIC_BUILTIN_DTB; then -- 2.42.0 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v1] kbuild: Add KBUILD_VMLINUX_LIBS_PRELINK 2025-11-19 4:27 [PATCH v1] kbuild: Add KBUILD_VMLINUX_LIBS_PRELINK Tiezhu Yang @ 2025-11-21 7:01 ` Nathan Chancellor 2025-11-21 18:42 ` Josh Poimboeuf 2025-11-22 1:35 ` Nathan Chancellor 1 sibling, 1 reply; 7+ messages in thread From: Nathan Chancellor @ 2025-11-21 7:01 UTC (permalink / raw) To: Tiezhu Yang Cc: Josh Poimboeuf, Ard Biesheuvel, Huacai Chen, linux-kbuild, linux-efi, loongarch, linux-arm-kernel, linux-riscv, linux-kernel On Wed, Nov 19, 2025 at 12:27:08PM +0800, Tiezhu Yang wrote: > In order to only link libstub to the final vmlinux, it can not use the > current KBUILD_VMLINUX_LIBS, just add KBUILD_VMLINUX_LIBS_PRELINK. This > is preparation for later patch, no functionality change. > > Link: https://lore.kernel.org/lkml/pq4h7jgndnt6p45lj4kgubxjd5gidfetugcuf5rcxzxxanzetd@6rrlpjnjsmuy/ > Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org> > Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> > --- > There is a long discussion in the previous patch: > https://lore.kernel.org/lkml/20250928085506.4471-1-yangtiezhu@loongson.cn/ > > This version is based on 6.18-rc6, split the generic parts out > into a separate patch to avoid merge conflicts, the other parts > will send out after the merge window. > > Makefile | 1 + > scripts/link-vmlinux.sh | 5 ++--- > 2 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/Makefile b/Makefile > index d763c2c75cdb..69485f47b794 100644 > --- a/Makefile > +++ b/Makefile > @@ -1199,6 +1199,7 @@ KBUILD_VMLINUX_OBJS := built-in.a $(patsubst %/, %/lib.a, $(filter %/, $(libs-y) > KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y)) > > export KBUILD_VMLINUX_LIBS > +export KBUILD_VMLINUX_LIBS_PRELINK This variable name is a little confusing to me since they do get added to vmlinux during linking, not before. I am not sure of a better one though, maybe KBUILD_VMLINUX_LIBS_FINAL? It may also make sense to introduce similar syntax to the existing libs-y syntax, maybe final-libs-y or something like that? Also, since these objects are no longer in KBUILD_VMLINUX_LIBS, does this new variable need to be added to any of the other places in the build system that use KBUILD_VMLINUX_LIBS for things such as build dependencies? > export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds > > ifdef CONFIG_TRIM_UNUSED_KSYMS > diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh > index 433849ff7529..e72d3254b93f 100755 > --- a/scripts/link-vmlinux.sh > +++ b/scripts/link-vmlinux.sh > @@ -61,12 +61,11 @@ vmlinux_link() > shift > > if is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT; then > - # Use vmlinux.o instead of performing the slow LTO link again. > objs=vmlinux.o > - libs= > + libs="${KBUILD_VMLINUX_LIBS_PRELINK}" > else > objs=vmlinux.a > - libs="${KBUILD_VMLINUX_LIBS}" > + libs="${KBUILD_VMLINUX_LIBS} ${KBUILD_VMLINUX_LIBS_PRELINK}" > fi > > if is_enabled CONFIG_GENERIC_BUILTIN_DTB; then > -- > 2.42.0 > ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v1] kbuild: Add KBUILD_VMLINUX_LIBS_PRELINK 2025-11-21 7:01 ` Nathan Chancellor @ 2025-11-21 18:42 ` Josh Poimboeuf 2025-11-22 0:01 ` Nathan Chancellor 0 siblings, 1 reply; 7+ messages in thread From: Josh Poimboeuf @ 2025-11-21 18:42 UTC (permalink / raw) To: Nathan Chancellor Cc: Tiezhu Yang, Ard Biesheuvel, Huacai Chen, linux-kbuild, linux-efi, loongarch, linux-arm-kernel, linux-riscv, linux-kernel On Fri, Nov 21, 2025 at 12:01:40AM -0700, Nathan Chancellor wrote: > > @@ -1199,6 +1199,7 @@ KBUILD_VMLINUX_OBJS := built-in.a $(patsubst %/, %/lib.a, $(filter %/, $(libs-y) > > KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y)) > > > > export KBUILD_VMLINUX_LIBS > > +export KBUILD_VMLINUX_LIBS_PRELINK > > This variable name is a little confusing to me since they do get added > to vmlinux during linking, not before. I am not sure of a better one > though, maybe KBUILD_VMLINUX_LIBS_FINAL? I think that name was my idea. Not sure what I was thinking, I guess "prelink" was somehow meant to imply after the vmlinux.o whole-archive link but before the "final" link. "final" is indeed better. > It may also make sense to > introduce similar syntax to the existing libs-y syntax, maybe > > final-libs-y > > or something like that? Yeah, I suppose that would mirror how KBUILD_VMLINUX_LIBS is wired up. > Also, since these objects are no longer in KBUILD_VMLINUX_LIBS, does > this new variable need to be added to any of the other places in the > build system that use KBUILD_VMLINUX_LIBS for things such as build > dependencies? Not sure about that one. drivers/firmware/efi/libstub/lib.a is getting built regardless so there must already be an implicit dependency? -- Josh ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v1] kbuild: Add KBUILD_VMLINUX_LIBS_PRELINK 2025-11-21 18:42 ` Josh Poimboeuf @ 2025-11-22 0:01 ` Nathan Chancellor 0 siblings, 0 replies; 7+ messages in thread From: Nathan Chancellor @ 2025-11-22 0:01 UTC (permalink / raw) To: Josh Poimboeuf Cc: Tiezhu Yang, Ard Biesheuvel, Huacai Chen, linux-kbuild, linux-efi, loongarch, linux-arm-kernel, linux-riscv, linux-kernel On Fri, Nov 21, 2025 at 10:42:47AM -0800, Josh Poimboeuf wrote: > On Fri, Nov 21, 2025 at 12:01:40AM -0700, Nathan Chancellor wrote: > > > @@ -1199,6 +1199,7 @@ KBUILD_VMLINUX_OBJS := built-in.a $(patsubst %/, %/lib.a, $(filter %/, $(libs-y) > > > KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y)) > > > > > > export KBUILD_VMLINUX_LIBS > > > +export KBUILD_VMLINUX_LIBS_PRELINK > > > > This variable name is a little confusing to me since they do get added > > to vmlinux during linking, not before. I am not sure of a better one > > though, maybe KBUILD_VMLINUX_LIBS_FINAL? > > I think that name was my idea. Not sure what I was thinking, I guess > "prelink" was somehow meant to imply after the vmlinux.o whole-archive > link but before the "final" link. Yeah I could see where you were going with that but glad we agree final is better heh. > "final" is indeed better. > > > It may also make sense to > > introduce similar syntax to the existing libs-y syntax, maybe > > > > final-libs-y > > > > or something like that? > > Yeah, I suppose that would mirror how KBUILD_VMLINUX_LIBS is wired up. On second thought, it might be less complicated to keep it this way... > > Also, since these objects are no longer in KBUILD_VMLINUX_LIBS, does > > this new variable need to be added to any of the other places in the > > build system that use KBUILD_VMLINUX_LIBS for things such as build > > dependencies? > > Not sure about that one. drivers/firmware/efi/libstub/lib.a is getting > built regardless so there must already be an implicit dependency? I think the explicit dependency currently comes from vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS) in Makefile. I think something like diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux index cd788cac9d91..38b5f0ba9a4b 100644 --- a/scripts/Makefile.vmlinux +++ b/scripts/Makefile.vmlinux @@ -68,7 +68,7 @@ cmd_link_vmlinux = \ $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true) targets += vmlinux.unstripped .vmlinux.export.o -vmlinux.unstripped: scripts/link-vmlinux.sh vmlinux.o .vmlinux.export.o $(KBUILD_LDS) FORCE +vmlinux.unstripped: scripts/link-vmlinux.sh vmlinux.o .vmlinux.export.o $(KBUILD_LDS) $(KBUILD_VMLINUX_LIBS_FINAL) FORCE +$(call if_changed_dep,link_vmlinux) ifdef CONFIG_DEBUG_INFO_BTF vmlinux.unstripped: $(RESOLVE_BTFIDS) is needed to ensure that an updated drivers/firmware/efi/libstub/lib.a results in vmlinux getting regenerated (at least according to my testing). Cheers, Nathan ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v1] kbuild: Add KBUILD_VMLINUX_LIBS_PRELINK 2025-11-19 4:27 [PATCH v1] kbuild: Add KBUILD_VMLINUX_LIBS_PRELINK Tiezhu Yang 2025-11-21 7:01 ` Nathan Chancellor @ 2025-11-22 1:35 ` Nathan Chancellor 2025-11-22 11:26 ` Tiezhu Yang 1 sibling, 1 reply; 7+ messages in thread From: Nathan Chancellor @ 2025-11-22 1:35 UTC (permalink / raw) To: Tiezhu Yang Cc: Josh Poimboeuf, Ard Biesheuvel, Huacai Chen, linux-kbuild, linux-efi, loongarch, linux-arm-kernel, linux-riscv, linux-kernel On Wed, Nov 19, 2025 at 12:27:08PM +0800, Tiezhu Yang wrote: ... > index 433849ff7529..e72d3254b93f 100755 > --- a/scripts/link-vmlinux.sh > +++ b/scripts/link-vmlinux.sh > @@ -61,12 +61,11 @@ vmlinux_link() > shift > > if is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT; then > - # Use vmlinux.o instead of performing the slow LTO link again. Why is this comment getting removed? > objs=vmlinux.o > - libs= > + libs="${KBUILD_VMLINUX_LIBS_PRELINK}" > else > objs=vmlinux.a > - libs="${KBUILD_VMLINUX_LIBS}" > + libs="${KBUILD_VMLINUX_LIBS} ${KBUILD_VMLINUX_LIBS_PRELINK}" > fi > > if is_enabled CONFIG_GENERIC_BUILTIN_DTB; then > -- > 2.42.0 > ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v1] kbuild: Add KBUILD_VMLINUX_LIBS_PRELINK 2025-11-22 1:35 ` Nathan Chancellor @ 2025-11-22 11:26 ` Tiezhu Yang 2025-11-23 21:15 ` Nathan Chancellor 0 siblings, 1 reply; 7+ messages in thread From: Tiezhu Yang @ 2025-11-22 11:26 UTC (permalink / raw) To: Nathan Chancellor Cc: Josh Poimboeuf, Ard Biesheuvel, Huacai Chen, linux-kbuild, linux-efi, loongarch, linux-arm-kernel, linux-riscv, linux-kernel On 11/22/25 09:35, Nathan Chancellor wrote: > On Wed, Nov 19, 2025 at 12:27:08PM +0800, Tiezhu Yang wrote: > ... >> index 433849ff7529..e72d3254b93f 100755 >> --- a/scripts/link-vmlinux.sh >> +++ b/scripts/link-vmlinux.sh >> @@ -61,12 +61,11 @@ vmlinux_link() >> shift >> >> if is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT; then >> - # Use vmlinux.o instead of performing the slow LTO link again. > > Why is this comment getting removed? When using KBUILD_VMLINUX_LIBS_PRELINK or KBUILD_VMLINUX_LIBS_FINAL, drivers/firmware/efi/libstub/lib.a needs to be linked to the final vmlinux with vmlinux.o, so I thought the above comment is not proper, it I misunderstood it, I will keep the comment as is. >> objs=vmlinux.o >> - libs= >> + libs="${KBUILD_VMLINUX_LIBS_PRELINK}" >> else >> objs=vmlinux.a >> - libs="${KBUILD_VMLINUX_LIBS}" >> + libs="${KBUILD_VMLINUX_LIBS} ${KBUILD_VMLINUX_LIBS_PRELINK}" >> fi >> >> if is_enabled CONFIG_GENERIC_BUILTIN_DTB; then FYI, the previous patch is still under discussion yesterday [1], I do not know whether this patch is necessary and what is the next step [2]. [1] https://lore.kernel.org/loongarch/CAAhV-H4AasfFet_Gi_mVyte3RPMH3qBS73dBfF-=Gd7HJ6ZPEw@mail.gmail.com/ [2] https://lore.kernel.org/loongarch/39617a3e-c476-abac-8425-bbcece769cdb@loongson.cn/ Thanks, Tiezhu ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v1] kbuild: Add KBUILD_VMLINUX_LIBS_PRELINK 2025-11-22 11:26 ` Tiezhu Yang @ 2025-11-23 21:15 ` Nathan Chancellor 0 siblings, 0 replies; 7+ messages in thread From: Nathan Chancellor @ 2025-11-23 21:15 UTC (permalink / raw) To: Tiezhu Yang Cc: Josh Poimboeuf, Ard Biesheuvel, Huacai Chen, linux-kbuild, linux-efi, loongarch, linux-arm-kernel, linux-riscv, linux-kernel On Sat, Nov 22, 2025 at 07:26:52PM +0800, Tiezhu Yang wrote: > On 11/22/25 09:35, Nathan Chancellor wrote: > > On Wed, Nov 19, 2025 at 12:27:08PM +0800, Tiezhu Yang wrote: > > ... > > > index 433849ff7529..e72d3254b93f 100755 > > > --- a/scripts/link-vmlinux.sh > > > +++ b/scripts/link-vmlinux.sh > > > @@ -61,12 +61,11 @@ vmlinux_link() > > > shift > > > if is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT; then > > > - # Use vmlinux.o instead of performing the slow LTO link again. > > > > Why is this comment getting removed? > > When using KBUILD_VMLINUX_LIBS_PRELINK or KBUILD_VMLINUX_LIBS_FINAL, > drivers/firmware/efi/libstub/lib.a needs to be linked to the final > vmlinux with vmlinux.o, so I thought the above comment is not proper, > it I misunderstood it, I will keep the comment as is. I think this comment is referring to the use of vmlinux.o instead of vmlinux.a, nothing to do with libs=, so I think the comment should remain. > > > objs=vmlinux.o > > > - libs= > > > + libs="${KBUILD_VMLINUX_LIBS_PRELINK}" > > > else > > > objs=vmlinux.a > > > - libs="${KBUILD_VMLINUX_LIBS}" > > > + libs="${KBUILD_VMLINUX_LIBS} ${KBUILD_VMLINUX_LIBS_PRELINK}" > > > fi > > > if is_enabled CONFIG_GENERIC_BUILTIN_DTB; then > > FYI, the previous patch is still under discussion yesterday [1], > I do not know whether this patch is necessary and what is the next > step [2]. > > [1] https://lore.kernel.org/loongarch/CAAhV-H4AasfFet_Gi_mVyte3RPMH3qBS73dBfF-=Gd7HJ6ZPEw@mail.gmail.com/ > [2] https://lore.kernel.org/loongarch/39617a3e-c476-abac-8425-bbcece769cdb@loongson.cn/ Thanks, we will wait to see the conclusion of those threads before applying this. Cheers, Nathan ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2025-11-23 21:15 UTC | newest] Thread overview: 7+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2025-11-19 4:27 [PATCH v1] kbuild: Add KBUILD_VMLINUX_LIBS_PRELINK Tiezhu Yang 2025-11-21 7:01 ` Nathan Chancellor 2025-11-21 18:42 ` Josh Poimboeuf 2025-11-22 0:01 ` Nathan Chancellor 2025-11-22 1:35 ` Nathan Chancellor 2025-11-22 11:26 ` Tiezhu Yang 2025-11-23 21:15 ` Nathan Chancellor
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).